package com.kan.awaits.id;

import java.net.InetAddress;


public abstract class AbstractUUIDGenerator implements IdentifierGenerator
{
	private static final int IP;
	static
	{
		int ipadd;
		try
		{
			ipadd = BytesHelper.toInt(InetAddress.getLocalHost().getAddress());
		} catch (Exception e)
		{
			ipadd = 0;
		}
		IP = ipadd;
	}
	private static short counter = (short) 0;
	private static final int JVM = (int) (System.currentTimeMillis() >>> 8);

	public AbstractUUIDGenerator()
	{
	}

	/**
	 * Unique across JVMs on this machine (unless they load this class in the same quater second - very unlikely)
	 */
	protected int getJVM()
	{
		return JVM;
	}

	/**
	 * Unique in a millisecond for this JVM instance (unless there are > Short.MAX_VALUE instances created in a millisecond)
	 */
	protected short getCount()
	{
		synchronized (AbstractUUIDGenerator.class)
		{
			if (counter < 0)
				counter = 0;
			return counter++;
		}
	}

	/**
	 * Unique in a local network
	 */
	protected int getIP()
	{
		return IP;
	}

	/**
	 * Unique down to millisecond
	 */
	protected short getHiTime()
	{
		return (short) (System.currentTimeMillis() >>> 32);
	}

	protected int getLoTime()
	{
		return (int) System.currentTimeMillis();
	}

}
